The impact factor of an academic journal for any year is the number of times the average article published in that journal in the previous two years are cited in that year. From 1994-2005, the average impact factor of journals listed by the ISI has been increasing by an average of 2.6 percent...

Transplants of donated stem cells save the lives of many patients with blood diseases. Donation is somewhat painful, but rarely has lasting adverse effects. Patients can accept transplants only from donors with compatible immune systems. Those lacking a sibling match must seek donations from the...

The plight of multiracial leukemia patients who are unable to find matching stem cell donors has received much media attention. These news stories, while dramatic, are short on statistical information and long on misconceptions. We apply simple probability theory, the genetics of sexual diploid...

This paper studies a general class of pure exchange economies that have multiple equilibria, which extend an example presented by Lloyd Shapley and Martin Shubik. For such economies, we find easily verified conditions that determine whether there are multiple equilibria. We also provide simple...

When academic journals were distributed only as paper editions, the obvious way for scholars to share a journal was to use the copy found on the shelves of their own university library. With the arrival of electronic access, the logistics of journal-sharing has changed radically. Physical...

When second-price auctions have been conducted in the laboratory, most of the observed bids have been “overbids†(bids that exceed the bidder’s value) and there are very few underbids. Few if any of the subjects in those experiments had any prior experience bidding in auctions....

The experimental economics literature on second-price sealed-bid private value auctions has established that subjects typically bid more than their value, despite the fact that value bidding is a dominant strategy in such auctions. Moreover, the laboratory evidence shows that subjects do not...

This paper contributes to the literature on second-price auctions with resale. We add speculators—bidders with value zero—to the standard symmetric independent private values environment. There always exists a continuum of inefficient equilibria that are profitable for a...

In nonconvex environments, a sunspot equilibrium can sometimes be destroyed by the introduction of new extrinsic information. We provide a simple test for determining whether or not a particular equilibrium survives, or is robust to, all possible re…nements of the state space. We use this...